Almeida, Ana G.Pinto, Fausto J.2018-07-192018-07-192013-10Postgrad Med J 2014;90:208–2150032-5473http://hdl.handle.net/10451/34255This is a reprint of a paper that first appeared in Heart, 2013, Volume 99, pages 1535-1542. Copyright © 2018 The Fellowship of Postgraduate Medicine. All rights reserved.engjournal article10.1136/postgradmedj-2012-302048rep